From: Andrea Parri <andrea.parri@amarulasolutions.com>
To: linux-kernel@vger.kernel.org
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jorgen Hansen <jhansen@vmware.com>,
Peter Zijlstra <peterz@infradead.org>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
"Paul E. McKenney" <paulmck@linux.ibm.com>
Subject: [PATCH 0/2] Prevent evaluation of WRITE_ONCE()
Date: Fri, 24 May 2019 12:35:34 +0200 [thread overview]
Message-ID: <1558694136-19226-1-git-send-email-andrea.parri@amarulasolutions.com> (raw)
Hi all,
This all started when we realized that
atomic64_t v;
...
typeof(v.counter) my_val = atomic64_set(&v, VAL);
is a valid assignment on some architectures, but not on others [1]:
in particular, the assignment is valid on all architectures #define
-ing their atomic64_set() macro to WRITE_ONCE() (which is currently
evaluated).
Mark suggested to clean up all non-portable users of atomic*_set(),
and to prevent WRITE_ONCE() from being evaluated [2]; this resulted
in this first attempt/patchset based on Mark's atomics/type-cleanup
branch [3].
Cheers Andrea
[1] https://lkml.kernel.org/r/20190523083013.GA4616@andrea
[2] https://lkml.kernel.org/r/20190523141851.GA7523@lakrids.cambridge.arm.com
[3] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git atomics/type-cleanup
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Andrea Parri (2):
vmw_vmci: Clean up uses of atomic*_set()
compiler: Prevent evaluation of WRITE_ONCE()
include/linux/compiler.h | 5 ++---
include/linux/vmw_vmci_defs.h | 4 ++--
2 files changed, 4 insertions(+), 5 deletions(-)
--
2.7.4
next reply other threads:[~2019-05-24 10:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-24 10:35 Andrea Parri [this message]
2019-05-24 10:35 ` [PATCH 1/2] vmw_vmci: Clean up uses of atomic*_set() Andrea Parri
2019-05-24 10:39 ` Peter Zijlstra
2019-05-24 11:40 ` Greg Kroah-Hartman
2019-05-24 11:59 ` Andrea Parri
2019-05-24 11:56 ` Andrea Parri
2019-05-24 10:35 ` [PATCH 2/2] compiler: Prevent evaluation of WRITE_ONCE() Andrea Parri
2019-05-24 10:53 ` Mark Rutland
2019-05-24 11:24 ` Andrea Parri
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